classmember text - iahmr · • fire protection engineers handbook and fire protection handbook -...

/-/qJ fov,

FDIC 2002

Instructors: John 8. Sachen Missouri University Fire and Rescue Training Institute

Glenn Jirka Missouri University Fire and Rescue Training Institute

Classmember Text

This classmember text is copyrighted material. It is illegal to copy any or all of this document for any reason without written permission from Fire Technology Ltd.

© Fire Technology Ltd, 2002

IGNITABLE LIQUIDS AND CLASS B FOAM CLASSMEMBER TABLE OF CONTENTS

TABLE OF CONTENTS

CHAPTER DESCRIPTION

Objectives and Properties of N-Heptane

Introduction

Ignitable Liquids

II How Foam Works

HI Choosing a Nozzle

IV F.ductors

v Practical Systems

VI Attack Techniques

VII Large Diameter Storage Vessels

VIII How Much Foam

IX Contaiiier Cooling

x OSHA HAZWOPER

Appendices

References:

•Case Study Notes 1958-2002 - John B. Sachen

• Chemistry of Hazardous Materials - 2nd Edition - Eugene Meyer

•Condensed Chemical Dictionary- 11th Edition - SAX

•EPA 40CFR311 • Fire Protection Engineers Handbook and Fire Protection Handbook - NFPA

• Fire Protection Manual for Hydrocarbon Processing Plants - Charles H. Vervalin

• Flammable Hazardous Materials - James H. Meidl

• Foam Engineering Manuals - Ansul, National Foam and 3M

• Principles of Fire Protection Chemistry - Richard L. Tuve

•OSHA 29CFR1910.120 (q) HAZWOPER Regulation/OSHA CLP2-2.59A Compliance Guideline

• Riegel 's Handbook of Industrial Chemistry - 7th & 11th Editions - Kent

• What Went Wrong? - Trevor A. Kientz

FIRE TECHNOLOGY LTD. 222 Bellevue Street

Cape Girardeau, Missouri 63701

Local Pager: 573-277-9911, Long Distance Pager: 800-222-6651(ID8097)

Phone: 573-332-1155, Fax: 573-339-1629 Original line art copyrighted by Fire Technology Ltd. Original Line Art Created by Bethany E. Sachen

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@FireTechnology Ltd, 2002 T1 (Original 6[18; Rev 8/98; Rev 4/02)

IGNITABLE LIQUIDS AND CLASS B FOAM OBJECTIVES

OBJECTIVES 1. Complete the course study guide and pass the end of class test

2. Define these terms and identify three important properties of ignitable liquids for firefighters:

Hydrocarbon Vapor Pressure Flash Point Fire Point

Roll On Vapor Density LFUUFL Aspirating

Rain Down IDLH Frothing Liquid Density

Permeation Sealing Insulating PPM

By-Pass AFFF Polar Solvent Boil Over

BLEVE Concentration Drainage Interf acial Tension

3. Predict vapor behavior for three spill situations.

4. Name two contributing factors for boil over and frothing.

5. List the five functions of Class B foam.

6. Identify four causes of eductor and nozzle failure.

7 Compare aspirating to non-aspirating foam nozzles on hydrocarbon and polar solvent fires.

8. Compare wetting/emulsifying agents to Class B foam agents on typical Class B spills and fires.

9. List three hazards concealed by foam blankets and two ways to reduce risk while working in foam.

10. Calculate delivery rate and quantity of foam concentrate required for a typical tanker spill fire.

11. As a team member: a.) Set up and operate a foam hand line with nozzle and eductor.

b.) Evaluate and trouble shoot two foam hand line systems.

c.) Extinguish two flammable liquid fires with foam and/or dry chemical.

N-HEPTANE Water clear volatile ignitable liquid: flash point 25F (- 3.9C), vapor density 3.5, LFL/UFL 1.05 - 6.7%,

liquid density 0.654, auto ignition 433F (222C), TLV 400ppm, and soluble in alcohol, ether, and

chloroform. CAS 142-82-5. Use: anesthetic, solvent, octane test standard, organic synthesis, and lab

reagents. Formula CH3(CH2)5CH3 or C7H16.

©Fire Technology Ltd, 2002 01 (Original 6!78; Rev 8198; Rev 4/02)

IGNITABLE LIQUIDS AND CLASS B FOAM

INTRODUCTION

1.SAFETY Safety is the top priority at situations involving ignitable liquids. This emphasis is valid both on the fire ground and during training.

This classmember text incorporates procedures and techniques that place safety first. Since agents, appliances and practices are under constant development, class members are asked to notify Fire Technology when they become aware of a new appliance, practice or agent that would affect this text.

2. ACKNOWLEDGMENTS This document is based on published information from the manufacturers of foam and foam appliances and from recognized texts and references.

It presents the best recommendations on foam types, application rates, appliances, and low risk application techniques now available. Fire Technology especially thanks these manufacturers for their assistance:

Ansul Akron Elkhart MS A-Research National Foam 3M

I. IGNITABLE LIQUIDS

1. WHAT ARE IGNITABLE LIQUIDS

Class B foam agents are intended for use on ignitable liquids, which are defined for this text, as materials that are liquid at room temperature (20°C/68°F) and atmospheric pressure (See NFPA 30).

©Fire Technology Ltd, 1998 1

CLASSMEMBERTEXT

Materials which boil below room temperature are considered gases.

Examples: A.) Ethyl ether, which boils at 34.5°C (94.1°F), is

considered a liquid; B.) Butane a gas, which boils at -0.5°C (31.1°F),

can be seen as a liquid under pressure in transparent lighters. If the lighter top is suddenly removed the butane will boil away to a gas.

Note: Ignitable liquids are referred to as: a.) Solvents

c.) Crudes b.) Reactants

d.) Products e.) Precursors f.) Flammables We will use the word products.

2. IGNITABLE LIQUID CHARACTERISTICS

Ignitable liquids have many different characteristics.

s The color of lamp oil and the odor of gasoline, are of limited value to firefighters. The color is from dyes and odor can't be detected in an SCBA.

Characteristics of importance to firefighters: Vapor pressure Flash point Flame spread Miscibility Ignition temperature Fire point Heat layering Froth over Boiling temperature Burn rate Boil over Liquid density Vapor density Entrainment

(Original 6n8; Rev 8/98)


Warning: In addition to the fact that ignitable liquids will burn, many are also toxic, corrosive, explosive, etc.

• Some, like monomethylamine, are flammable and corrosive gases that can be dissolved in water!

3. VAPOR PRESSURE Vapor pressure is the push that vapors exert when they escape the surface of a liquid as the result of molecular movement. With heat input both movement and pressure increase.

VAPOR SPACE

I HEAT~. L~~ HEAT

~ l~i~flti' ::QUID

Vapor pressure is usually measured at 20°C (68°F). At that temperature, the vapor pressure of many ignitable liquids is high enough to be read on standard gauges.

IMPORTANT: The correct term for the molecules of a liquid in air, is vapor, not fumes. Fumes are the airborne particles from welding or grinding - or the fog like cloud from fuming corrosives such as fuming nitric acid.

4. FLASH POINT Flash Point may be defined as the temperature of a liquid, when it's vapor flashes at the surface, with an ignition source present.

Flash Point is determined using apparatus similar to that demonstrated in the class.

© Fire Technology Ltd, 1998 2

CLASSMEMBER TEXT

~ , ,

After the flash the flame ceases due to limited vapor supply at that temperature. (At very low temerpatures molecular movement is slow and no vapor will be detected above a liquid.)

IMPQRTANI: On the fire ground, flash point is normally the most fact about an ignitable liquid. Even if the flame goes out, it could still ignite paper, weeds or a similar material.

5. FIRE POINT Fire Point is the temperature of a liquid at which the ignited vapors will continue to bum.

The Fire Point temperature can be as little as a few tenths of a degree above the flash point to many degrees higher.

6. THE FIRE SQUARE

Several geometric figures help us understand fire. For this program we will use the Fire Square.

THE FIRE SQUARE I FUEL ~OXIDANT!

THE HANDSHAKE

CHEMCIAL REACTION

0

~ F

~ x m.L u I r;:~ E D

A L

N E Oxygen Any gas, tiquidor T Clorine and Fluorine

solid that will burn in the oxidant

(Original sns; Rev 8/98)


7. COMBUSTION REACTIONS -SIMPLIFIED (Formulas are not balanced and intermediate combustion products are not shown.)

H + 0 = H20 + L:. +

CLASSMEMBERTEXT

Combustion is a rapid oxidation reaction resulting in a variety of products of combustion, including light, heat, solids, gases and pressure.

p

Hydrogen Oxygen Water Heat Pressure

c + 0 = C02 Carbon Oxygen Carbon

Dioxide

CH4 + 0 = C02 Methane Oxygen Carbon

Dioxide

s + 0 = S02 Sulfur Oxygen Sulfur

Dioxide

H + Cl = HCI Hydrogen Chlorine Hydrogen

Clo ride

+

+

+

+

co + Carbon Monoxide

GO + Carbon Monoxide

6 + Heat

6 + Heat

c Free Carbon

+ L:. Heat

+ p Pressure

c + H20 + L:. + P Free Carbon

Water Heat

p + (H20 = H2S03 ) Pressure Water Sulfurous

Acid

p + (H20 = HCl/H20) Pressure Water Hydrochloric

Acid

Pressure

Warning: Combustions are complex reactions with toxic intermediate and final compounds.

8. VAPOR DENSITY The molecules of ignitable liquids are heavier than those of oxygen or nitrogen, the major component gases of air. Vapors of ignitable liquids at room temperature will sink in still air.

<;;.;> '>. AIR_..~,,...,.---

LFL-+ UFL-+

50/50 4-- ..

100% VAPOR -+ LIQUID __.. v (( ({I{/ I II

Vapor Density of Common Materials Acetone: 2.00 Gasoline: 4.10 Kerosene: 4.50 Methane: 0.60 Methanol: 1.11 Toluene: 3.14


9. VAPOR BEHAVIOR

Vapors of liquids at room temperature sink, but they also:

A.) Move with ambient air flow which can result in a hazardous atmosphere higher in a space than expected.

FRESH AIR

IGNITION f SOURCE ~ ~

~~ +

SPILL OR EXTINGUISHED FIRE

(Original sn8; Rev 8/98)

IGNITABLE LIQUIDS AND CLASS 8 FOAM

B.) Rise and fall, or undulate, as they move down wind over a distance. This is most evident with natural gas type odors (mercaptan).

Rise and fall is evident in the smoke from tliis gasoline tanker fire.

C.) Travel down the center of shifting or variable winds.

WIND

~ ± 15° DOWN THE CENTER

D.) Are less concentrated in moving air. The evaporation rate of the liquid depends primarily on the area of the spill and the temperature of the liquid.

Smph Wind 1*-1 O ppm -+I

10mph Wind 1*- 5ppm -+I

Air moving over a spill lias little effect on release rate. So the faster the air flow, the more dilute the concentration.


CLASSMEMBERTEXT

E.) Hot vapors expand and rise by convective flow. They can be ignited above the release.

EXTINGUISHED FIRE '-)I>'''

HOT RISING VAPORS

"' )

IMPORTANT: Near field wind direction can change up to 180°, between building and vehicles with only a few degrees change in the far field wind.

Vapors are not normally visible, except as vapor density shadows in bright sunlight, this increases the risk of working around vapor releases.

Warning: Ignitable liquids are sometimes heated during a manufacturing process. They may also be hot following a fire extinguished with dry chemical.

Vapor updraft can easily be seen during fire conditions

(Original 6fl8; Rev 8/98)


10. WATER MISCIBILITY

Most critical characteristics, such as vapor pressure, affect all ignitable liquids in the same way. One exception is water miscibility, which divides ignitable liquids into two distinct groups.

These two groups are generally referred to as: A.) Hydrocarbons (or hydrocarbon like)

which do not mix with water. (And)

B.) Polar solvents which are miscible.

Hydrocarbons (Non miscible)

Gasoline

Lube oil

Kerosene

Toluene

Polar Solvents £Miscible)

Acetone·

Alcohol

Ethyl ether

Ethylene glychol

IMPORTANT; It is possible to extinguish polar solvents by dilution but it is very difficult:

a.) Water will push the burning material.

b.) Both must be well mixed.

c.) Some products require as much as a 22:1 dilution ratio (This means 2200 gallons of water for 100 gallons of solvent).

While hydrocarbons are considered nonmiscible, all are miscible to some degree.

NOT ALL CONNECTIONS HAVE AP-TRAP!


VAPORS TO BASEMENTS

CAN EASILY BY ABOVE THE LFL!

5

CLASSMEMBERTEXT

Toluene, which has a miscibility of less than 700 ppm, can produce ignitable vapors in sewer systems operating above 37.8°C (100°F).

Vapors leave the aqueous liquor and collect in the stagnant head space where they can exceed the lower flammable limit.

11. MISTS, SPRAYS AND AEROSOLS

Misting occurs when liquids are released under pressure from nozzles, from breaks in hose or piping, when they are ejected from moving vessels or when vapors cool. Mists are also referred to as sprays and aerosols.

~~--·_ ~ ~""'- _-_-_ ~l?t:_~ -

Warm vapors and mists that contact cool air can condense to a visible cloud, sometimes referred to as a "White Ghost".

WARNINGS:

1.) Liquids that normally will not ignite because they are colder than their flash point are ignitable as mists or sprays.

2.) Mists and sprays can't be detected with LFL detectors.

12. FLAMMABLE OR COMBUSTIBLE

Ignitable liquids are divided into two groups based on their flash point temperature.

The temperature of the dividing line under the NFPA classification system was 37.8C (lOOF).

This temperature is also used by the U.S. OSHA.

IMPORTANT: The temperature 11ow used by the the

Natitmal Fire Protection Association (NFPA) a11d U.S.

Department of TransportoJion (U.S. DOT) is 60°C (140°F)

in compliance with international standards.



Classification Chart (Degrees Fahrenheit)

Product Flash Point Ignition Temp

Lube oil 375 700

Antifreeze 232 750

Navy fuel oil 140 400

Kerosene/diesel 110/135 410

Safety solvent 105 450

-NFPA-37.8°C (100°F)-

Varnish 080 475

Methyl alcohol 055 860

Toluene 040 990

Acetone -0 870

Ethyl Ether -50 350

Gasoline -55 650

Remember: Use the ABC's and you will always remember combustible and flammable:

A

B

Combustible

-NFPNU.S. DOT-59.9°C (141F)

D

E

Flammable

IMPORTANT: While liquids, such as diesel fuel, can

sometimes be extinguished with water; extinguishing a

large diesel fire with water is virtually impossible!

13. FLAMMABLE LIMITS

Flammable limits are the lowest and highest concentrations of a vapor in air that are ignitable (Lower concentrations are to lean to bum and higher concentrations are to rich).

IMPORTANT: Flammable limits are also known as explosive limits. Vapor/air mixtures can burn fast enough to produce pressure waves.

This type of low order (slow) explosion is referred to as a deflagration.


CLASSMEMBERTEXT

If an ignition source is brought from outside the vapor cloud, a point will be reached where the vapor is rich enough to ignite. The vapor concentration is the lower flammable limit (LFL) in percent.

'N\~~ ··--

1.8% 10.0%

If the ignition source starts in the rich vapor zone, and is moved toward the lean zone, a spot will be found where the vapor to air concentration will support ignition. This concentration is the upper flammable limit (UFL).

Concentrations between the two . values are the flammable range of the product.

Vapor concentrations can be measured with combustible gas indicators (COi's) and low risk zones identified.

Selected Flammable Limits

Liquid Lower (LFL) Upper (UFL)

Acetone 2.6% 12.8%

Benzene 1.5% 8.0%

Propane 2.4% 9.5% Toluene 1.7% 9.5%

Ethyl Ether 1.9% 36.0%

14. HEALTH LIMITS

OSHA generally considers a vapor concentration that is less than 10% of the LFL to be fire safe (a reasonable fire risk).

Warning: While a concentration less than 10% of the LFL may not pose a high fire or explosion risk, it usually presents a significant health risk.



SCBA is required until the IC detennines otherwise by air

m01iitoring. Generally tllis is below the tliresliold limit value (TLV). Reference: OSHA 29CFR1920.120(q).

15. FIRE AND HEALTH RISKS COMPARED

Percent Parts/Million ~PPM~ Comment 100.0 1,000,000 All vapor/No Air 50.0 500,000 50150 Vapor/ Air 25.0 250,000 10.0 100,000 UFL - Gasoline 1.8 18,000 LFL - Gasoline 0.18 l,800 10% ofLFL 0.02 200 IDLH - Gasoline 0.005 50 *TLV - Gasoline 0.0005 ±5 Odor threshold

(Gasoline) *Respiratory protection required above this

concentration.

16. FLAME SPREAD

Flame spread is the speed that flames will cross an open area of product at a specific liquid temperature, usually 20°C (68°F).

At 20°C, fire will cross kerosene at 40 feet per minute, but in that same minute, fire will cross 750 feet of JP-4, a mixture of gasoline and kerosene:

Kerosene - 40'

JP-4 750'

Warning: If kerosene is heated to 103°C (220°F) by an industrial process or by a fire, it's flame speed will then be 750 feet per minute/!


CLASSMEMBER TEXT

17. HEAT WAVES - BOILOVER - FROTHING

A.) Heat waves (layers) and boilover:

Heat waves or layers are formed by the radiant heat of the flames or from heat conducted by the vessel sides. The heat wave moves slowly down through the liquid.

Low boiling temperature liquids, such as diesel and gasoline, burn away fast enough to prevent formation of heat waves that are hotter than the boiling point of water 100°C (212°F).

There still is a heat wave, it's just not hot enough to boil water.

Warning: If there is a water bottom in the vessel, the water will boil when the heat wave reaches it. The contents will be violently ejected in the boil over, placing everyone in the area at grave risk!!

High boiling temperature liquids, like crude oil, roofing tar and asphalt, allow a heat wave over 100°c (212°F) to form.

Products like creosote can form dangerous heat zones when their light ends burn away.

(Original 6fi8; Rev 8/98)


B.) Frothing:

Violent frothing occurs when foam or water is applied on top of a high boiling liquid that is hot.

NOTE: Large diameter vessels are less likely to froth over.

18. ENTRAINMENT Entrainment occurs when gas pressure in a vessel is suddenly released and bubbles form in the liquid due to boiling or from a dissolved gas. This occurs when a rnanway, rupture disk, pressure relief, or drum is opened or ruptures.

~::·

i,;,;1:~,

IMPORTANT: Up to 50% of the contents can be entrained when the bubbles form in the liquid and carry it out like champagne.

Vertical containers loose 10% to 50% of their contents. Vessels on their side loose 100% and rocket!

19. IGNITION TEMPERATURE

The temperature of a hot surface or atmosphere that ignites vapors of a liquid is usually considered the ignition temperature of the liquid .

., © Fire Technology Ltd, 1998

8

CLASSMEMBERTEXT

Warning: Some low Ignition temperature liquids, such as carbon disulfide 100°c (212°F) and ethyl ether 161°C (325°F), can be ignited by a cigarette.

High ignition temperatures are easily exceeded by flares, electrical arcing and lighters.

20. STATIC ELECTRICITY

High voltage static charges are developed when materials are separated or pass by each other.

This is frequently observed when a spark from your hand jumps to a door knob after you cross a carpet.

Static is the cause of many ignitions and is a subject of continued study by industrial safety specialists.

Warning: Foam or water from a nozzle, carbon dioxide from an extinguisher, any liquid flowing through a hose or a plastic pipe - all of these can generate a spark that will ignite vapors!

21. LIQUID DENSITY

Density refers to the molecular weight of a liquid compared to water - Does one quart of gasoline weigh more or less than one quart of water?

The presence of many low density liquids, like gasoline, can lead to a mistaken belief that a all ignitable liquids are less dense than water and will float.

Depending on the composition of the molecule, a liquid may be lighter, the same, or heavier than water (Less, equal, or more dense).

AIR

Carbon disulfide, creosote, and some road tars are more dense than water and can be extinguished by flooding.



II. HOW FOAM WORKS

1. FIRE IS EXTINGUISHED BY A.) Cooling fuel below the flash point.

B.) Sealing in the fuel vapors. C.) Excluding air (smothering). D.) Interrupting the chemical reaction.

There is no ideal agent that does all of these tasks on ignitable liquids - but water that floats does the first three.

2. MAKING WATER WORK Water can extinguish some high flash point liquids under very favorable circumstances.

s~· But usually a water only attack is not successful. Water can be modified to float on ignitable liquids by adding air to it! The air is mixed using mechanical energy and is held in the bubbles by surfactants (surface modifying agents).

AIR FINISHED ~ FOAM

FOAM SOLUTION) ~I IJ :t ,.......II-., '/<

FOAM CONCENTRATE

AIR

Class B Foam consists of water, foam concentrate, and air.


CLASSMEMBERTEXT

Foam floats because of the air. Foams keep floating because they are engineered hold air for long periods of time.

Class B fire fighting foams extinguish fire by:

a.) Cooling d.) Separating

b.) Sealing e.) Insulating

c.) Smothering

SEALS THE SURFACE

IMPORTANT; Class B foams break down and drain, a disadvantage. A stiff foam would last longer but would not flow easily over the liquid surface or around obstacles.

3.) COOLING

The reduction of the temperature of the vessel and liquid by the cooling action of the water.

A well proportioned foam in the range of 4: 1 to 15:1, has sufficient water to cool the liquid surface, vessel sides, and other hot materials. It is fluid enough to flow around obstructions and be stable in moderate winds.

4.) SEALING

A.) General:

Sealing is accomplished because of the weight of the foam blanket, which is lighter than the fuel but heavier than the vapors.

Foam blankets must be renewed on a regular basis. Testing with LFL detectors is a good indicator of the condition of the foam blanket.

Warning: As they drain, even the most effective foam blankets are slowly permeated by the vapors under pressure. When the foam has drained for a long time the vapor/air mixture can be ignited. This is more common with high expansion foams and very fast draining foams.



B.) Sealing and AFFF's While all Class B foams will seal, one group of synthetic agents, AFFF's (Aqueous Film Forming Foams), use some of the foam solution to aid the sealing. The addition of the perfluorocarbon film forming agent increases the interfacial tension of the solution.

SEE APPENDICES I & 2

Increasing the interfacial tension of the foam solution forms a floating 1-3 rnircon thick film from the drained solution. This adds to sealing, but is not a separate action!

5. INSULATING:

A.) General: Fire fighting foams consist of bubbles (cells of air surrounded by foam solution). This insulating function has great importance to the life of the foam and keeping the unignited or extinguished liquid cool.

~ n Courtesy National Foam

B.) Insulating and AFFF's: Essentially, the thin AFFF film has no insulating value. Either direct flame contact or radiant heat break down the film quickly. It's the insulating action that keeps foam working.

©Fire Technology Ltd, 1998

CLASSMEMBERTEXT

Flame on film - poof!

6. SMOTHERING: Smothering is preventing air from reaching the vapors. It is a separate function from sealing but is closely related to it. In general, a foam that seals well also does a good job smothering.

5. SEPARATION: Separation is the action of the blanket as it crosses the surface of the liquid, lifting the flames. Important: A film of AFFF solution is not effective in the separation function on hot liquids for three reasons:

A.) It vaporizes easily. B.) The surface tension of gasoline and similar

products is very low when they are hot and the film drops through.

10

C.) The high vapor pressure of the hot liquid pushes through the film.

IMPORTANT: AFFF film does not seal well on cold high vapor pressure liquids.

8. CRITICAL RATE Manufacturers test foams to find the minimum (critical) rate that must be used for extinguishrnent. This is usually expressed in gallons of foam solution per minute, per square foot. As a safety factor, the recommended rate is three times the critical rate. Critical Rate .......

5

4

3

2

.05 .1

J Maximum Recommended ,.. Rate

.2 .3 FOAM SOLUTION U.S. GPM/SO. FT.

{Original 6n8; Rev 8/98; Rev 01.01; Rev4/0)

-IGNITABLE LIQUIDS AND CLASS B FOAM CLASSMEMBERTEXT

9. POLAR SOLVENT FOAM 10. CHARACTERISTICS OF GOOD

Polar solvents attack all foams by diluting the CLASS B FOAM

water at the bottom of the foam cells.

REGULAR NON-POLAR/AFFF

~ CELLS BURST HERE

POLAR SOLVENT

To resist the attack by the polar solvents, a water

soluble gum (natural plastic) is added to the foam

concentrate.

POLAR/AFFF

POLAR SOLVENT

The additive is not miscible in polar solvents and

as the foam blanket breaks down the gum additive forms a floating layer.

The gum layer slows the vapor attack on the remaining foam.

Facts about Polar I AFFF foam:

A) The gum layer does not form on hydrocarbons.

B.) The additive results in a longer lasting, slower draining foam.

C.) Usually the application rate for polar liquids is

higher than for hydrocarbons.

D.) Application rates for hydrocarbon and polar

solvents vary according to supplier. Be sure to

use the specified rate.

© Fire Technology ltd, 1998 11

• Flows easily over ignitable liquids and

around obstructions.

• Seals against hot metal and hold in vapors.

• Resists fuel pickup when flaked (rained

down) on the product surface.

• Insulates unignited or extinguished pro

duct from radiant heat and direct flame

contact.

• Resists bum back from extinguished fire.

• Extinguishes fires in high vapor pressure

liquids.

11. OTHER FOAMS

Foam types tested and approved for high vapor

pressure Class B fires include: Protein, Fluoro

protein, FFFP (Film forming fluoroprotein

foam), AFFF and Polar/ AFFF.

In addition, another group of agents have a U.L.

listing for fires involving combustible liquids.

These agents were initially developed as wetting

agents for Class A materials and/or to emulsify

Class B materials.

The underwriters fire test for these agents is sub

stantiaUy less severe than the test for full service

Class B foams.

At present none of these emulsifying and/or wet

ting agents are listed for high vapor pressure liq

uids or polar solvents. And they require signifi

cant application and agitation to reduce vapor

release from a large surface.

(Original 6/78; Rev 8/98)

IGNITABLE LIQUIDS AND CLASS B FOAM CLASSMEMBERTEXT

Generic Comparison of Foam Characteristics Courtesy: National Foam

Characteristic

Knockdown

Flame/Heat

Resistance

Resistance to

Fuel Pickup

Vapor Sealing

Resistance to

Polar Materials

© Fire Technology ltd, 1998

Foam Type

Emulsmer/

Wetting Agent Fluoroprotein AFFF FFFP Polar/AFFF

Poor/Fair Good Excellent Good Excellent

Poor Excellent Good Good Good

Poor Excellent Fair Good Fair/Good

(It is an emulsifier)

*Poor/fair Excellent Good Good Good

None None None Fair Excellent

U.L. CLASS B FIRE TEST COMPARISON Foam and Emulsifier/Wetting Agent

U.L. 162 Foam equipment & liquid concentrates

55 Gallons Heptane

2GPM

3 minutes or less for complete extinguishment

Two tests during a nine minute waiting period

Required after foam blanket holds for nine minutes

Polar/AFFF is tested by U.L. for use on alcohols and

other polar solvents

12

No U.L. standard assigned. Test program on file at U.L.

55 Gallons Heptane

10GPM

None

None

None

None

Not comparable agents, as indicated by separate

listings and test criteria

The same fire challenge for both types of agents

Five times higher application for same test criteria

Unlimited fuel dilution as long as test pan does

not overflow

Confirms the ability to seal against hot metal, and prevent vapor release

Critical test for post fire security

Oxygenated gasoline additives are polar solvents, and may require polar resistant foam

based on National Foam infonnation



III. CHOOSING A NOZZLE

1. EXPANSION

Expansion is the ratio of the finished foam to the foam solution which indicates the amount of air aspirated into the foam.

With a 10: 1 expansion ratio, a 1 OOgpm foam nozzle would add 900 gpm ( 11 Ocuft) of air to the foam.This produces 1000 gpm of finished foam.

As noted in Section III, expansion ratio is important because it affects drain time and the insulating properties of finished foam.

Expansion ranges for the four types of nozzles commonly used with foam are:

Nozzle Type Typical Expansion Ratios

Fog

Aspirating tube

Medium Expansion

High Expansion

4:1to6:1

8:1to15:1

50:1 to 100:1

100:1 to 500:1

Expansion ratios that work well on outdoor spills are in the range of 4:1 and 15:1 (Air to solution ratio).

Above 15: 1, wind begins to adversely affect the foam blanket.

2. FOG (NON-ASPIRATING) NOZZLES

Foam solution droplets from "fog" nozzles collide with air like the liquid in a child's bubble ring and foam bubbles are formed.

The foam is actually aspirated in the air and the droplets vary in size and speed. The resulting foam bubbles are unequal in size and wall thickness.

)~~~i~

Collapse occurs between the large and small cells which can result in accelerated drainage, higher vapor release, and the need for higher application rates.


CLASSMEMBERTEXT

IMPORTANT: In the early stage of foam application to spill fires of civilian jet fuel (kerosene) and on large diameter open tank fires, a non-aspirating nozzle can be more effective.

3. FOAM (ASPIRATING) NOZZLES

13

Foam solution sprayed into the end of the tube causes a low pressure zone with a vacuum action that pulls in air. The air mixes with the solution in the tube, forming a finished foam that has more consistent cell sizes and is slower draining.

AIR

~ ~~ FOAM SOLUTION~~

This results in a lower velocity stream that may be less disturbing to the surf ace of the liquid but which also has less reach.

The lower velocity of aspirating nozzles means that 300 gpm foam nozzles can be hand held for short periods of time.

Courtesy National Foam



One manufacturer has developed a fog nozzle with the option of adding air at the center of the baffle plate. This produces an aspirated foam from a fog nozzle.


4. DRAIN TIME WITH AFFF Average of three different nozzles -(Courtesy 3M)

Drain time is the time for 25% of the solution to drain from a foam with a specific nozzle in a carefully defined test.

Foam Type

Non-Aspirating Nozzle

Regular AFFF 1:30 min.

(1%, 3%, 6%)

Polar AFFF 2:53

(1%, 3%)

Polar AFFF 6:40

(2x Hydrocarbon rate)

Aspirating Nozzle

4:20 min.

9:10

23:00

IMPORTANT: The drain time of an aspirated Polar/AFFF foam is 3.5 times longer than a non-aspirated foam.


CLASSMEMBER TEXT

S. FOAM/FOG NOZZLE COMPARISON (Courtesy: Mobile Oil Research)

TESTl

Fuel: Unleaded Gasoline; Tank Size: 800 Sqft.

Prebum: l Minute; Application rate: 0.7 GPM/Sqft.

Nozzle

Foam

Fog

TEST2

Control Time Extinguishing Time

0:40 1:20

2:00 2:23

Fuel: Leaded Gasoline; Tank Size: 37' diameter;

Prebum: 5 minutes; Application Rate: 2 GPM/10 Sqft.

Nozzle Control Time Extinguishing Time

Foam 1 :30 Min 3:25 Min

Fog 5:35 Min 6: 10 Min

IMPORTANT: Manufacturers of Polar/AFFF foams state that aspirating nozzles must be used for fires involving polar solvents!

6. HIGH EXPANSION

High expansion foam, which has a very high air to solution ratio, was developed in Great Britain for coal mines where the ability to fill a void is very valuable.




Air blows into the foam solution as it is sprayed on a screen or net producing expansion ratios ranging from 100:1 to 500:1 (Some generators can produce 1000: 1 expansion but the foam has limited use).

500:1

SJ-AIR

High expansion foam nozzles have very short reach and the finished foam is unstable in wind. Vapor pressure will push vapors into the foam blanket.

High expansion foam works well in certain exterior applications where an engineered design is used, such as with liquefied natural gas (LNG) storage facilities.

©Fire Technology Ltd, 1998

CLASSMEMBERTEXT

15 (Original 6/78; Rev 8/98)


IV. EDUCTORS

1. HOW EDUCTORS WORK

Eductors are syphons that work because a liquid (or a gas) flowing through a restricted venturi area creates a pressure drop. This vacuum pulls the foam concentrate up the tube.

WATER~

t FOAM CONCENTRATE

There must be flow through the eductor. If the flow is restricted or stopped (either at the inlet or the outlet) the suction will not be sufficient to pull the correct percentage of foam into the eductor.

Most eductors require 175-200 psi inlet pressure. With a 100 gprn nozzle and 300 feet of t 3 / 4" line, the pressure drops will be similar to this:

+--300'--+ EDUCTOR 1 314 • LINE

(60 psi LOSS) (40 psi LOSS) . 100psi

WATER

2

00ps•y::;:OLUTION\~o.'o' ::;~~}

FOAM CONCENTRATE

How nozzles and hose adversely affect pick-up of foam concentrate:

--::ii~·

-/\"- t WATER OUT HERE KINKS


CLASSMEMBER TEXT

A.) The nozzle is partially closed.

B.) The nozzle is too small. C.) The nozzle is much higher than the

eductor. D.) The hose line is too long or kinked.

s [~

~ PARTIALLY CLOSED

NOZZLE TOO SMALL

s~s t' ~~ NOZZLETOOFAR J=4 "°""'*%$'P'4\*t%1'iS:OVE EOUCTOR

~~ •J<.t "

200' 1112

2. WHY EDUCTORS DON'T WORK

A.) They aren't clean.

B.) They leak.

C.) They don't match the nozzle.

HOSE KlNKEO OR TOO LONG

~ CLOG



3. TROUBLE SHOOTING

Trouble shooting an eductor is easy with a hydrant, two sections of line and a shut off with no tip.

~50'--Jo>

40·100psi

SGALBUCKET OF WATER

A.) First remove all attachments such as the metering orifice, check valve and pick-up hose.

B.) Flow water and insure that the orifices are clean and a vacuum is present.

C.) Check the flow rate of the eductor with an adjustable flow tip.

D.) Put on all of the parts in sequence until it doesn't work, then fix the last item.

4.CLEANING

Dried foam concentrate can be softened and removed with hot water and trisodium phosphate.

Always flush an eductor after use with five gallons of water (warm if possible).

If the tubing in a built-in system is clogged it may have to be replaced.

5. NOZZLES WITH PICK-UP TUBES

Foam pipes with pick-up tubes are a combination of an eductor and a nozzle and thus, they operate on lower pressures.

Courtesy Akron Brass

IMPORTANT: They also operate over a wider range of inlet pressures and flows than separate nozzle and eductor combinations. This is a vety valuable feature during overhall.


CLASSMEMBER TEXT

6. MATCHING NOZZLES AND EDUCTORS

An inherent limitation of standard eductors is that they work efficiently at one specific flow rate.

;~-::

60GPM NOZZLE

I

.. ·;!,:n··'' ..... , .... ,.-.·V·"'"'···.··.··.····· ... ·.~ .... v:~·::-"

.,., 60 GPM t ;;j

'\, EDUCTOR) /

~ Courtesy National Foam

IMPORTANT: No Flow or a Restriction = No foam concentrate pick-up.

The type of nozzle does not change that.

7. IT MAY STILL WORK

A.) At low Pressures.

Even if you don't have 200 psi at the eductor, the system will probably work if the nozzle matches the eductor.

60gpm EDUC TOR

60gpm NOZZLE

~'"'"" ~"'"''• . . ··: :::\~::.{:~:~~:'.:

I SHORT I FOAM CONCENTRATE REACH

The percentage of foam concentrate will increase and the nozzle will have short reach but you will make foam.

B.) With a Large Nozzle.

A nozzle with a flow rate higher than the eductor will make foam but the reach will be reduced because of low pressure.

95gpm EOUCTOR

125gpm NOZZLE

R=i~~:;i:;; D I SHORT I

FOAM CONCENTRATE REACH

IMPORTANT: The eductor will pick up even with no nozzle on the hose - of course aspirated foam would not be produced!



8. COMPENSATING EDUCTORS

Pressure compensating eductors are now available that work over a wide range of inlet pressures and flows.

FOAM INLET \...-.-,. CHECK VALVE

PRESSURE BALANCING VALVE

CONNECTORS FIT HERE

I ---ti SOLUTION

~ FLOW

Courtesy Spumifzer

Because of their lower pressure losses they can be left in the piping on preconnected lines.

Courtesy Angus

Compensating eductors have higher preventive maintenance needs and must be flushed very carefully. They are also more expensive than standard eductors. Compensating eductors are available from Angus and Spumifier.


CLASSMEMBERTEXT

9. AUTOMATIC NOZZLES:

18

Automatic nozzles are designed to maintain a constant inlet pressure, over a range of flows, for the best discharge pattern.

The design pressures are between 60 psi and 100 psi. This is accomplished with a spring controlled baffle that may also shape the stream in the discharge barrel.

95GPM

60GPM

4-.~~~~

=t: If the pressure at the inlet to the eductor drops from 200 psi to 150 psi, the spring in the nozzle will compensate to keep 100 psi at the nozzle inlet - but at reduced flow, which may stop foam pick-up at the eductor. (Under these same circumstances a fixed flow nozzle would make foam, however the reach would be reduced). IMPORTANT; Automatic nozzles should be tested with specific hose lengths and pump pressures. Otherwise the system may not work.



V. PRACTICAL SYSTEMS

1.SYSTEMA A 60 psi or 100 gpm low cost system ($450-$600) consisting of a shutoff and foam nozzle with pick-up tube. It is very effective on passenger vehicles and is excellent for overhall on larger incidents.


Several higher rate nozzles, up to 300 gpm are also available with pick up tubes.

Courtesy Cape Girardeau Fire Department

2.SYSTEMB An assembly with a shut off, eductor, nozzle, hose and fittings that allows the eductor to be 50-300 feet from the nozzle.

Courtesy National Fo01n

© Fire Technology ltd, 1998

CLASSMEMBERTEXT

Preassembling System B components with straps

or an equipment bag puts foam on the fire in one

two minutes. Cost is in the range of $1200-

$1500.

3.SYSTEM C

19

Built-in systems using bypass eductors offer the

option of either water or foam from a precon

nected line.

Courtesy Cape Girardeau Fire Departme11t

Since 60, 95, or 125 gpm eductors cost the same,

it is usually prudent to install the highest delivery

rate eductor.

IMPORTANT; With patience, favorable circumstances

and good technique, a 60 gpm system can extinguish

a fire in a 9, ooo gaflon tanker.

A. Typical Piping.

"·~... ~'. .. ~

Courtesy Akro11 Brass

IMPORTANT: The additional piping and valves

increase the need for operator knowledge and practice

with by-pass systems.

(Original ans; Rev 8/98)


B.) In the By-Pass Setting

125 psi BYPASS OPEN

125 psi

C I --+~-+--+~ I n \ 'c::::=> ---+---.L..---IEl~.-.. -L~-AJg~giiLE PUMP

NO PRESSURE DROP AND NO FOAM PICK UP

With this arrangement the pump discharge and outlet gauge will read the same, less any piping loss.

C.) In the foam Setting

200psi

n PUMP

BY PASS CLOSED

t FOAM CONCENTRATE

140psi

-+ TOHOZE ,..-------+--r-AND NOZZLE

With the by-pass valve closed the eductor is in the line, there is a pressure drop across the venturi and foam concentrate is picked-up.

The outlet gauge wil1 read less than the pump gauge, by the the drop across the eductor.

© Fire Technology Ltd, 1998 20 (Original 6fi8; Rev 8/98)


VI. ATTACK TECHNIQUES

I.GENERAL A.) Preplan for expected incident types, include

both fixed and highway sites. B.) Start ICS before leaving the station. C.) This is a hazmat incident - treat it as such. D.) Request assistance while enroute. E.) Approach from up wind and up hill.

2. PASSENGER VEHICLES Tires may be flat and the vehicle will be close to the ground with a 10-20 minute prebum.

Courtesy Nati.onol Foam

Immediate Action: Cool with a 95-125gpm water line while putting foam in service. Use care to cool the hot metal and not wash fuel toward an exposure.

Dry chemical usually will not be effective due to hidden fuel sources and prebum.

Application Technique: Foam and damn the runoff that threatens exposures, then start foam around the vehicle.


CLASSMEMBERTEXT


Build the blanket and force foam under the vehicle and into voids. Extinguish the interior and overhall witli foam.

Dry chemical can then be used to complete the extinguishment.

Keep foam and dry chemical ready for reignitions and watch out for reactive metals with car fires.

3. ALUMINUM TANKERS

Most modem tankers are constructed of aluminum which has greatly reduced the risk of a BLEVE.

Heat or flame impingement melts the shell before the contents can heat above their boiling temperature.



Most tanker fires result in early melt down to the product level. After melt down, the burning product will boil over, pool around the tanker and then flow down grade.

Warni~gs:

1.) lgrlitions In compartments are still possible.

2.) Bottom and head failures have happened with enough force to move trailers on landing gear.

3.) Do not climb on trailers or other vessels to foam a compartment. The metal is slippery and sharp. The footing Is poor and a splash can cover a firefighter in a fire ball.

Courtesy Fi.re House Magazine


CLASSMEM$ER TEXT

Immediate Action: Cool the area and p~otect exposures. Dam the run-off from a low risk ~ocation. Operations Level responders can do tiiis -See Section IX and OSHA 29CFR1910.12Q(q).

Foam Technique: If possible approach frohi up wind, off to the side, and with a safety lineJ

Use the rain down method or a trough madd from I

guttering.

Shut off water where the foam is startibg to work!

If the ground fire is large, extinguish /it first before approaching the tanker. Otherwis¢ use a rain down pattern on the tanker and all~w the excess foam to overflow onto the ground lfire.

i

i

From up wind, start with the closest compart-ment. A down wind approach can increase the foam demand by three times!

Adjust the pattern and rate to apply the foam as gently as possible:

a.) Roll on - The least disturbing.

b.) Bounce off - Watch for Splashing.

c.) Rain down (Flake) - Don't Plunge.

d.) Hold the nozzle steady!

Hold the nozzle steady!

e.) Extinguish one compartment before going to the next.



Warning: Stay out of the foam blanket if possible: Hazards of walking in foam blankets: a.) Stepping in holes. b.) Tripping and entanglement. c.) Liquid pick-up and chemical

exposure. If you must approach the tanker, constantly measure vapor concentration.

Alternately slide each foot slowly forward to find holes or tripping hazards and to reduce the product splashed on bunker gear. Have Dry Chemical ready! Decontaminate bunkers immediately to eliminate ignition hazard and lower risk of chemical exposure.

Overhall must be with foam, including tires, cab seats, underbrush, etc. That's where the 150-200 gallons of foam concentrate will be used.

This is the time that the 60 gpm foam nozzle with pick-up tube comes in handy.


CLASSMEMBERTEXT

IT'S OUT and IT'S YOURS -BUT IT'S NOT EMPTYH

It may take many hours to obtain equipment and pump out the remaining product. Use a strainer when you pump off the product.

Call for more foam, relief, your state environmental group, more air, food and coffee.

Keep the mayor, media, spectators, and untrained firefighters, carrier and clean-up reps back at the coffee wagon.

Monitor for LFL and TLV. IMPORTANT: Safety limits are much higher than health limits. The lower flammable limit for gasoline is 2% (20,00ppm), but the IDLH is .002% (200ppm)!!

4. 1,000-50,000 GALLON TANKS A.) Old horizontal types.

Old installations lack adequate venting to relieve the pressure from fire under tanks. In addition the tank supports lack fire proofing.

Most new tank farms do not include horizontal tanks or their risks have been reduced by thermal insulation and larger vent areas.

Warning: This is a very dangerous fire. Rocketing tanks are likely and a BLEVE is possible.

Early collapse of the steel supports is normal!!



Immediate Action: Start continuous cooling water from both sides. A minimum of 500-7 50gpm from each unattended master stream.

See section IX on Container Cooling

Place the appliances under cover of fog streams to reduce the risk from radiant heat.

Adjust the streams to keep water on the exposed vapor space of the vessel and the piping.

CLASSMEMBERTEXT

B.) Small-Medium Vertical Tanks

The techniques are similar to horizontal tanks except that the roofs will sometimes fail and foam must be projected over the top. If aerial apparatus is necessary, use the least valuable that meets the need.

Warning: Don't put firefighters at the top, they will be exposed to the greatest heat flux if a fire ball occurs. Warning: ff this action is not possi'?le; if

there are any signs of pressure; or if you 5 FLANGE AND PIPE FIRES are unsure of the situation, leave the • area.

Cool exposures with unattended lines from a distance and watch for rocketing vessels. Foam Technique: Start from the side with at least a I 00 gpm nozzle while still applying water. Slowly shift the water away as the foam begins to work. This fire will require a substantial amount of foam. You may have to let it bum if it involves damaged valves and pipe with flowing fire.

IMPORTANT: Once started, foam must be continued. If polar materials are involved the foam blanket will break down more quickly.


Flange fires involve a pressure release from a failed or loose part. The hazards they present and the mitigation techniques are similar for all pipe-line components such as unions, valves, pumps, check valves, etc.

A.) Trapped liquid in pipes - boom!

B.) Increased release rate/reach C.) Impact on vesseVother devices.

Immediate Action: Protect exposures, control fire or stop the flow by closing valves, clamping, diverting, or replacing product with water. Then extinguish the fire with foam. Foam Technique: Use foam to protect adjacent piping if it can be applied from low risk locations. Insure that foam use will not reduce supplies below the minimum needed for final extinguishment.

(Original 6ns; Rev 8/98)


VII. LARGE DIAMETER STORAGE VESSELS

Large diameter vessels present significant challenges beyond those associated with spills and small and medium tanks.

Warning: Only competent personnel should work with these fires.

Extinguishing efforts are difficult since large tanks fires are typically:

A.) 125 - 150 feet in diameter and approximately 42 feet high!

B.) Equipped with complex floating roof assemblies that have been damaged.

C.) In containment dikes with limited access.

D.) Include 8".:. 20" piping and pumps with fire in the dike area.


CLASSMEMBER TEXT

IMPORTANT: Successful use of low risk methods and techniques for large diameter tanks requires significant study, practice, and experience.

In general, successful control of large tanks includes these critical steps:

a.) Preplanning and incident action plans with alternates based on weather, fixed systems, personnel, etc.

b.) Adequate cooling of exposed vessels and piping with without flooding dikes.

c.) Collecting high volume foam equipment and foam concentrate for the initial and continuing attacks.

d.) Foam application to the cool zone from low risk locations with high volume appliances.

The cool zone is on the up-wind side where air is drawn into the fire. It is the area of low pressure and lowest heat impact on the foam.

Williams Fire and Hazard Control refers to this area as the Footprint (C) of the application zone.



VIII. HOW MUCH FOAM

1. TANKERS, SPILLS AND SHALLOW DIKES

A quick way to determine an adequate delivery rate and quantity for shallow spills, tankers and dike areas is:

A.) Multiply: diameter X diameter X 80% (This is the area of the spill).

B.) Divide the area by 10 (This is the application rate for hydrocarbons in gpm). The Quick Formula (50' diameter fire): 50' X 50' = 2500 X 80% = 2QOO = 200gpm

10 200gpm @ 3% = 6 gpm/foam for 20 minutes (120 gallons of concentrate). Dividing by 5 gives the rate for polar solvents (or 400GPM for this situation).

IMPORTANT: For fire areas that include large heavy pieces of metal, the foam application rate will be higher and foam concentrate need may be 2-3 times larger!

The need can be reduced by cooling with water.


CLASSMEMBERTEXT

On a typical diesel train incident, water application may take up to 60 minutes at 100-500 gpm.

2. LARGE DIAMETER DEEP TANKS

26

The Quick Formula (125' diameter tank): 125' x 125' = 15625 x 80% = 12500 =

*5 2500 gpm water (minimum) x 3% = 75 gpm foam concentrate x 60 minutes =

(4500 gallons of concentrate!!)

*The rate for spills and small diameter vessels is not high enough for large diameter tanks where long distances and wind are critical factors. In addition, the NFPA states that foam must be available for a 60 minute application on deep tanks. IMPORTANT: Recent tests show that non-aspirating nozzles in the 2,000-5,000gpm range improve knock down by over corning updraft and atmospheric wind. They also reduce risk by moving nozzles back from the fire zone.

At that point a change to aspirated foam can be very effective.

Fortunately polar solvents are not normally stored in very large diameter tanks, otherwise the numbers would double!



IX. CONTAINER COOLING

Many procedures are recommended for incidents involving ignitable liquids, including foam on the fire or spill, control of the fuel source, dry chemical, and cooling exposures. The most common instruction is to cool exposed containers. Typical is the North American Emergency Response Guide. Guides 127 and 128 state "Cool (exposed) containers with flooding quantities of water until well after the fire is out."

Courtesy Firehouse Magazine

The fue ball from on 55 gallon drum clearly demonstrates the need to take some effective action.

While container cooling recommendations have been around since the late I 800's, very little information has been published that shows if cooling has the desire effect. Firefighters at St. Louis Plant of Mallincrodt Chemical Company conducted a simple evaluation of water spray cooling. A standard DOT flammable liquid drum was equipped with three dial type thermometers, one in the vapor head space, one in the liquid space and one on the face of the head out of direct sunlight which measured air temperature before the test and water spray temperature during the test.


CLASSMEMBERTEXT

RED WHITE RED

,,~"\ \ \ s ....... ~.

To eliminate the hazard of an ignitable liquid, water was used in the container which was heated by the sun. Since horizontal containers usually present the largest surface area to the sun or to an exposure fire, the drum was place on its side. A red/white/red paint scheme was selected to average between a dark and light coating.

Vapor and liquid temperatures stabilized after three days and the test was conducted.

As is the case with actual incidents, a big challenge is to keep water on the container in variable cross wind, especially with the straight streams necessary to keep maximum distance. The temperature graph shows that water spray is very effective in lowering the temperature of both the head space and the liquid. The temperature of the water dropped 1°C due to evaporation as it traveled from the nozzle to the container. IMPORTANT: If the water you are applying is warmer than the exterior of the vessel, such as on a cloudy day or in the evening, you will be adding heat to the vessel rather than removing it!



co (F°)

44 (111.2)

43 (109.4)

42 (107.6)

41 (105.8)

40 (104.0)

39 (102.2)

38 (100.4)

l!? 37 ( 98.6) :l

~ 36 ( 96.8) CD c.. E 35 ( 95.0) ~

34 ( 93.2)

33 ( 91.4)

32 ( 89.6)

31 ( 87.8)

30 ( 86.0)

29 ( 84.2)

28 ( 82.5)

DRUM COOLING EXPERIMENT MSCC FIREFIELD 8/27193

---- WATER TEMPERATURE

• • • VAPOR SPACE ~:E L1 i:I,

• • • 1 • • • • • • AIR TEMPERATURE

···_·· ___ ····:··i·····--·-.··········r········1·········:·.··-.· ... ··.-·:·---·······r················-···

'r11~~;tJj ------~-- ······· -~ ....... .

00 04 08 12 16 20 24 28 32 36 40 44 48 52 56 60

Duration of Water Application (Minutes)

IMPORTANT: You may see an old photograph of drums stored on their sides. This storage method is not used today in modern plants that observe good safety practices.

moved on pallets, even single drums. Upright drums are more stable and less likely to roll than are drums on their sides. Upright drums do not have to be unrighted to move, which reduces risk to persons.

BLOCKS

G2)\ Drums are now stored upright and moved by fork lifts, two wheel trucks, or by rolling the upright on the chime. In fact, most drums are stored and


MISSING BLOCK

~ WARNING: Drums stored on their sides are likely to roll uncontrollably. Pyramid stacks are very subject to collapse due to the end drum slipping over the stop, a very hazardous situation.



Warning: Heated drums usually rupture around the chime in the vapor space. A side stored drum will rocket, releasing 100% of its contents. An end stored drum will usually remain upright and in place if it fails a the top chime. From 20-50% of the contents will be lost, most going up.

SIDE STORED DRUMS

HEAT HEATED CHIME ABOVE LIQUID

~ HEAD SPACE

LIQUID SPACE

(THE HEAD TOWARD THE HEAT USUALLY FAILS)

Remember - virtually all drums stored horizontally will rocket when they fail!

FAILURE AT CHIME (ALL CONTENTS EJECTED)

ROCKETING DRUM WITH THE ENERGY TO GO HUNDREDS OF FEET! (USUALLY AWAY FROM HEAn

END STORED DRUMS HEATED CHIME ABOVE LIQUID

HEAT

~ VAPOR SPACE

LIQUID SPACE

FAILURE AT CHIME {20·50% CONTENTS EJECTED)

DRUM REMAINS UPRIGHT


CLASSMEMBERTEXT

With low boiling temperature liquids, such as ethyl ether, boiling point 34.5°C (94.1°F), or with liquefied gas such as propane, firefighters are sometimes instructed to cool containers heated by direct sunlight.

At a recent propane incident with an afternoon temperature of 37°C (98.6°F), the pressure in a venting 500 gallon residential LP tank was lowered from 250psi to 220psi with a garden hose in less than five minutes. The relief valve reset and the LP supplier later pumped off the excess liquid.

WARNING: Be very careful when cooling a vessel, especially an LP tank or any liquefied gas container - do not allow any water to enter the relief valve or stack. If the container has been over filled and is venting a liquefied gas, the relief valve may be cold enough to freeze the water which could seal the tank!

{Original sns; Rev 8/98)

1-GNITABLE LIQUIDS AND CLASS B FOAM CLASSMEMBERTEXT

X. HAZWOPER 5. IMPORTANT HAZWOPER DEFINITIONS

1. PURPOSE AND SCOPE:

This class provides Hazwoper training that response agencies may consider for Operations Level competency for gasoline fires per OSHA 29CFR1910.120(q).

2. OBJECTIVES

A.) Define and list the characteristics of a hazardous materials emergency.

B.) Identify the federal regulation(s) governing hazardous materials response.

C.) Identify the characteristics and critical elements of gasoline incidents.

D.) List four requirements that apply to the IC at a gasoline incident.

3. REFERENCES A.) OSHA29CFR1910.120(q)- U.S. Code of

Federal Regulations.

B.) CPL2-2.59A Compliance Guideline for Inspections - USIDOL-OSHA.

C.) EPA 40CFR3 ll - U.S. Code of Federal Regulations.

D.) North American Emergency Response Guide -US/DOT

4. HAZARDOUS WASTE OPERATIONS AND EMERGENCY RESPONSE

(Federal Regulations OSHA 29CFR1910.210, March 6, 1989)

A.) Started as hazardous waste operations for treatment, storage and disposal facilities (TSD'S).

B.) Expanded to emergency response after comments from firefighters, etc.

C.) Now covers both private and public responders under OSHA 29CFR1910.210(q) and U.S. EPA 40CFR3l1 which covers non-OSHA states such as Missouri and adds reserve and volunteer responders to HAZWOPER.

D.) Requires employers (FD's and PD's) to have a comprehensive response plan.

NOTE: The plan can be considered a procedure or guideline. Federal regulations refer to these documents as plans.

© Fire Technology Ltd, 1998 3)

Employer: City, fire district, sheriffs office, etc.

Employee: Firefighter, police officer, medic, etc.

Site: 1. Private plant, business, etc.

(or)

2. Location: eg. 200' south of Hwy-Pon County Rd 263

Hazardous Material:

"Any substance or material in any form or quantity which poses an unreasonable risk to safety and health and to property when transported in commerce" (U.S. DOT)

6. IMPORTANT

An Incident Management (Command) System must be used and a competent IC must be in charge.

7. COMPETENCY REQUIREMENTS FOR RESPONDERS

A.) Awareness: Recognize, isolate and report, using the North American Emergency Response Guidebook (Non-operations firefighters, law enforcement, security, medics, and dispatchers).

B.) Operations: Protect persons, property and the environment in a defensive mode (Isolate and dam from a safe location, but take no direct action on the leak.)

C.) Technician: Plug the leak and/or neutralize the spill (Higher competency).

D.) Hazmat IC: IC with special hazmat competency (Operations plus 24 hours).

Notes:

1.) Initial training before new duties and annually there after.

2.) Operations level firefighters are in technical violation of Hazwoper when they handle gasoline and propane (To keep from being cited they must have additional training such as this class).

8). AN EMERGENCY IS:

A.) Generic definition: "A sudden, generally unexpected occurrence demanding immediate action"



B.) OSHA: AN EMERGENCY RESPONSE INCLUDES (But is not limited to, one or more of the following situations from CPL2-2.59A, Table B.l):

a.) The response is from outside the immediate release area;

b.) The release requires evacuation of employees in the area;

c.) The release poses, or has the potential to pose, conditions that are immediately dangerous to life and health (IDLH);

d.) The release poses a serious threat of fire or explosion (exceeds or has the potential to exceed the lower flammable limit);

e.) The release requires immediate attention because of imminent danger;

f.) The release may cause high levels of exposure to toxic substances;

g.) There is uncertainty that the employees in the work area can handle the severity of the hazard with the P.P.E. and the equipment that has been provided and the exposure limit could easily be exceeded; and

h.) The situation is unclear, or data are lacking on important factors.


CLASSMEMBER TEXT

9). SELECTED MANDATES FORM THE REGULATION

A.) When an inhalation hazard or potential hazard exists, SCBA shall be worn until the IC determines, through air monitoring, that SCBA are no longer required.

B.) The IC shall designate a SAFETY official who shall have authority to suspend, or terminate, activities if IDLH conditions exist.

C.) When operations are termillated the IC shall implement appropriate decontamination procedures.

D.) A direct quote from CPL2-2.5A: "As long as an emergency response team (Fire Agency) is still in control of the site and a safety or health hazard exists, the emergency situation continues in effect.

For example, if a vacuum truck arrives to remove spilled gasoline while the emergency response team is managing the activity, the vacuum truck operator's activity is part of the emergency response operations"

E.) Further, the IC must be sure that the emergency phase is over and/or that competent industry representatives are present before releasing the site.

NOTE: The IC has authority over and responsibility for private industry employees and outside contractors.

(Original 6/78; Rev 8/98: Rev 4/02}

fGNITABLE LIQUIDS AND CLASS B FOAM

I .. INTRODUCTION

SUBJECT~

Comparison of Class B Foam (Underwriters Laboratories UL-162) to Emulsifying Agents (UL-6N72).

REFERENCES: 1. MC-306 gasoline tanker roll-over, NBC fire

district at 0600, Sunday, June 11, 2000.

2. UL 162 standard for Class B Foam. 3. UL 6N72, a test procedure for wetting

agents.

4. Classmember Text with UL 162 to UL 6N72 comparison.

5. Appendix 2 - Properties of surfactants

ATIACHMENTS: 1. Photograph of uprighted tanker on I-55.

2. Application rates from the label of one wetting/emulsifying agent used for diesel and gasoline spills.

II. BACKGROUND

As early as 1904 specific agents (additives) were available to modify the properties of water for use on ignitable liquid spills and fires.

Early foam agents were two part dry compounds (known as: A and B powders).

The foam was filled with catbon dioxide gas from an acid/base chemical reaction, similar to the reaction in soda-acid fire extinguishers.

While complex by today's standards, the 1904 chemical reaction foams separated the flames from the liquid, sealed in vapors, excluded air, and both cooled and insulated the liquid.

These are the same properties and benefits offered by todays Class B foams. The A/B foam changed the way water worked with other liquids. Additives that do this are referred to as surfactants by the chemists.

Improvements, such as concentrated liquid agents, single agents for both hydrocarbon and polar liquids, long shelf life, water film forming properties, and increased fire extinguishing capability have occurred at regular intervals.

Appendix 2 lists surfactant properties common to firefighting.


APPENDIX 1

III. WHEREWEARETODAY

With the advances in Class B foam, command officers should have a good understanding of what to select for a spill or fire.

Unfortunately, confusion exists about the advantages of specific types of mitigating and extinguishing agents.

This situation is exacerbated by three things: 1. The increased popularity of agents to wet

Class A materials such as wood, paper, and vegetation.

2. The need for improved agents to clean-up spills.

3. An Underwriters Laboratory test for wet-ting agents on Class B fires.

The UL procedure for evaluating wetting agents was originally developed to test wetting agents on combustible liquids.

It is a procedure .. on file" for testing a wetting agent, not a UL standard.

rv. WHAT DOES UL 6N72 MEAN?

The wetting agent test is less challenging than UL 162 for Class B foams (Reference 4).

From the table it will be noted that wetting agents are applied at five times the rate for Class B foam, do not under go a bum-back test, and have no limit on application time, the test container just can't be overflowed. When wetting agents pass the they can be sold for use on Class B fires, with: "UL Listed Wetting Agent 6N72" on the label.

In major fire situations, knowledgeable command officers would likely select a UL 162 foam. Some suppliers are including an emulsifier along with the wetting agents that are sold under UL 6N72 (Appendix 2, emulsifiers).

Agents that wet and emulsify could be considered for a spill based on their ability to emulsify ignitable liquids, "rendering them incapable of sustaining ignition or re-ignition" (quote from emulsifier instructions).

(Original 6fl8; Rev 4102)


V. WHAT ABOUT A BIG SPILL?

Early Sunday morning, June 11, 2000 a roll over occurred at MP 75 on I-55 in the NBC, MO fire district and 8500 gallons of unleaded were released into a ditch with a water bottom. Two different agents are compared. The Class B foam: 1. UL 162 foam used to seal the smface and

reduce vapor concentration during the following operations: a. Dike and dam the ditch filled while

preparing the initial plan. b. Vacuum pick-up the product, the existing

water bottom, and the foam drainage. c. Right the tractor and trailer with a small

product release and metal to concrete friction contact.

This is the method used on the incident and the figure in comparison are actual amounts. The effectiveness of the foam blanket was validated using a PID (photo ionization detector) by MO/DNR.

Compared To: 2. Using a UL 6N72 wetting/emulsifying agent

to emulsify (mix) the product with water. Emulsification could reduce vapor pressure and the risk of ignition during clean-up operations. Calculations for this part of the comparision are based on application information from one supplier (ATTACHMENT 3):

"For one gallon of spilled fuel, add one quart of agent and a minimum of three gallons of water."

The quantity (gallons) and cost comparison:

Agent Unleaded Agent Water •Water Total

Type Fuel Quantity for Agent Bottom Llqnld

UL162 8500 125 4000 6700 19,300

Foam

Agent Cost $2,500

($20.00 gal)

UL6N72 8500 2,000 24,000 6700 41,200

Emulsifier

Agent Cost $20,000

($10.00 gal)

*Water recovered from the ditch during the ckan·up above the amount

used for foam.


APPENDIX 1

Costs would be higher for an emulsifying agent, Considering the increased water content of the waste which would increase disposal costs for redistillation or inceneration for cement production.

(Original 6nB; Rev 4/02}

--lo -c 4


I. WHAT MAKES···-

Wetting Agents - WET?

Foam Agents - FOAM? Emulsifiers - EMULSIFY? Defoamers-DEFOAM? Aqueous Film Fonning Foam - FILM?

SURFACTANTS· DOii

II. WHAT ARE SURFACTANTS?

Additives that change the way one material, such as water, interfaces with another, are referred to as swface active agents (swfactants) by chemists. Water poured on a freshly waxed car fonns well defined beads and .does not wet the hood. Add a wetting agent (sutfactant) and water spreads over the hood, wetting it! Water+ wetting agent (surfactant) =A wet hood!

Water poured on grease simply runs off, unless something is added to breakdown the grease. Water + soap (surfactant) + grease =Clean Dishes!

Pure water will not retain air forced into it by a blender once the power is turned off. But add a few drops of a surfactant and presto - FOAM! Water + foam (surfactant) + energy= Fire Foam

Surfactants could be considered the catalysts of physical interface. They change the way compounds, such as water, work physically with other materials (these are not chemical reactions). Regular firefighting foams, emulsifiers, film forming foams, and wetting solutions consist of water to which something has been added to change the way the water interfaces with both liquids or solids. Therefore, the agents used by firefighters for foaming, wetting, and emulsifying are surfac -tants! Surfactant activity was first discussed by scientists in the lSOO's.

While most surfactants give more than one property to water. usually a given surfactant has one strong property.


APPENDIX 2

III. UNDERSTANDING THEM

1. What is Surface Tension? Surface tension is the name for the attraction between water molecules that results in water "beading up". At the surface of water, the molecules don't have anything "above" them, so their attraction is focused on the molecules on each side. The resulting force pulls the water into drops which don't effectively wet the swface. This is called surface tension and it is very strong in pure water. Surface tension causes uneven brush streaks in fresh paint. It keeps lubricants from fully wetting bearings and cylinder walls and it keeps water from wetting a piece of cloth (the drops bridge across the individual fibers).

2. Bow Wetting Agents Change Things. Some sutfactants move to the surface of a liquid and reduce the attraction between the molecules, allowing the liquid to wet the surface. Swfactants are used in very large quantities by the paint and coating industry to reduce brush marks, also in lubricants to allow grease and oil to wet bearing surfaces, and in laundry detergents to wet the clothes!

Surfactants that lower surface tension for firefighting are called wetting agents. 3. Firefighting foam

Modem firefighting foam is a mixture of a liquid (water), wetting and foaming agents (surfactants). and a gas (air) in cellular form (bubbles). It is made using mechanical energy to mix the air with the liquid.

Water + foam + air + mechanical energy =foam

The mechanical energy may be from a pumper, an air compressor in the case of CAFs (compressed air foam), or stored air pressure in an extinguisher.

Surfactants are needed because the surface tension in pure water causes the bubbles to burst when the energy stops. Wetting and foaming are surfactant properties that are easily recognized by ftrefighters. Effective foam for ignitable liquids has enough air in the cells to float on the surf ace of ignitable liquids.

(Original 4/02)


4. What Else Does Firefighting Foam Do?

Firefighting foam insulates and slows the drainage of the solution to allow the other surfactant actions. such as wetting, to continue over a longer period of time. They also slow the release of vapors from the liquid. Related information: Solid or semi-solid foams such as urethane can be made by injecting a gas or by a chemical reaction that releases a gas in the liquid before it cures (sets up). Early firefighting foams were produced by a chemical reaction that released carbon dioxide when the agent was mixed with water.

S. Defoaming

A small number of surfactants actually destroy the cells of a foam, they are referred to as defoamers. Defoamers are of great value in paints, lubricants, food processing (particularly for cooking fruits, such as apples, which contain a natural foaming agent,. pectin). Defoamer reduce the impact of firefighting foam during system tests at industrial plants. Mineral oil is a defoamer for some cooking processes.

A combination of wetting surfactants and defoaming surfactants are often used in paint and lubricants. 6. Emulsification (What E soap/detergent?)

One of the most important uses of sutfactants is for cleaning, especially the removal of greases, oils and other hydrocarbon like materials from cloth, skin and metals.

Note: If we wished to only remove common dirt (inorganic materials) from cloth, we could use an agent that lowered surface tension and allowed the water to wet between the fibers and flush out the dirt - a wetting agent!!

Unfortunately, soiled materials usually include oil and grease which are not soluble in plain water.

Simply put, water and hydrocarbons don't mix because of a lack of physical attraction between the - CH radical at each end of the hydrocarbon and the - OH radical at each end of the water molecule!

I I

HHHHH I I I I I I

HCCCCCH I I

HOH I I I I

HHHHH I I I I I I

PENTANE I I

WATER I I I I I I


APPENDIX 2

REMEMBER: Low density hydrocarbons will float on water and high density hydrocarbons will sink, but they won't mix, even if they stand for years!!

A.fur Kerosene

Water Bunker oil

A surfactants that allows water to mix with oils and grease is an emulsifier! We usually call them soap, detergent, degreaser, soil release agent. etc.

Emulsifiers were mentioned in early Roman history when they recorded the fact that treating animal fat with wood ashes mad a soap that would remove grease from dishes and clothes.

Emulsifiers bridge between water and hydrocarbons by looking like water at one end of the molecule and like hydrocarbon on the other.

HHHHH HH

HCCCCCH=HCCOH --HOH

HHHHH HH PENTANE ETHYLALCOHOL WATER

Ethyl alcohol acts is the smfactant that allows water to mix with pentane, a hydrocarbon.

Heet (alcohol) is added to gasoline tanks to absorb the water condensation that forms in cold weather. Emulsification is not a desirable function for firefighting foam, because foam should form a vapor seal, not mix with the liquid

7. The Micelle

As early as the 1950's the fonnation of a ring of water molecules around a hydrocarbon molecule through surfactant action was described in Canadian literature as a micelle. The more common term for this function is emulsification. Micelles form with all soaps, detergents, and degreasers.

(Original 6{18; Rev 4/02)


8.Interfacialtension. The fact that the water molecule has an -OH radical at each end and the hydrocarbon molecule a -CH radical at each end (which do not "like" each other) creates a barrier between the dissimilar liquids. This barrier has a name, it is called interfacial tension.

HHHHH HHHHH HHHHH

Pentane HCCCCCH HCCCCCH HCCCCCH HHHHH HHHHH HHHHH

lnterfadal

Tunslon}

Water

------------------------------------------------------------HOH HOH HOH

Higher interfacial tension between the water and the hydrocarbon will increase the vapor sealing property of a foam blanket

It is also possible that some of the foam solution will form a thin film on the surface of the product.

Aqueous (water) based films can be formed with the addition of perfluorocarbon surfactants which are more expensive than wetting, emulsifying and foaming agents.

Foam blanket

•water based fDm

Interf'acial

Tension}

Hydrocarbon

(Pentane)

--HOH OOH HOH

HHHHH HCCCCCH

HHHHH

*with l"rfloorocarf>on sorfanants

NOTE:

Perfluorocarbon surfactants are used in large quantities by the fabric industry to "soil-guard" cloth.


APPENDIX 2

m. PROPERTIES BY USE

Surfactant mixtures are formulated for specific tasks or applications.

SURFACTANT USE ACTION

TYPE Lube Oii Pat A.FFF Class A Foam Detergent

Lower Surface

TunsJoo (Wet) x x x x x Rain Interradal

Ttasloo x Foam x x x De-Foam x x Emulsify x

Notes:

l. While the surfactant properties can be described separately, individual surfactants usually will cause more than one action.

2. Formation of a "gum" layer by a Polar-AFFF agent and a miscible liquid like alcohol, is a precipitation rather than a surfactant action.

3. Virtually all wetting surfactants also foam in high concentrations.

This can be observed with Class A foams. In low concentrations (.05%) Class A foam reduces surface tension low enough to adequately wet natural cover fires for mop-up or for structural fire overhaul (with very little foaming).

As concentration increases the water foams easily with long drain times, similar toAFFPs.

(Original 4/02)

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